package net.area80.utils
{
	import flash.utils.ByteArray;   
	    public class Base64Coder {   
		        private static  const encodeChars:Array =    
			        ['A','B','C','D','E','F','G','H',   
				        'I','J','K','L','M','N','O','P',   
				        'Q','R','S','T','U','V','W','X',   
				        'Y','Z','a','b','c','d','e','f',   
				        'g','h','i','j','k','l','m','n',   
				        'o','p','q','r','s','t','u','v',   
				        'w','x','y','z','0','1','2','3',   
				        '4','5','6','7','8','9','+','/'];   
		        private static  const decodeChars:Array =    
			        [-1, -1, -1, -1, -1, -1, -1, -1,   
				        -1, -1, -1, -1, -1, -1, -1, -1,   
				        -1, -1, -1, -1, -1, -1, -1, -1,   
				        -1, -1, -1, -1, -1, -1, -1, -1,   
				        -1, -1, -1, -1, -1, -1, -1, -1,   
				        -1, -1, -1, 62, -1, -1, -1, 63,   
				        52, 53, 54, 55, 56, 57, 58, 59,   
				        60, 61, -1, -1, -1, -1, -1, -1,   
				        -1,  0,  1,  2,  3,  4,  5,  6,   
				         7,  8,  9, 10, 11, 12, 13, 14,   
				        15, 16, 17, 18, 19, 20, 21, 22,   
				        23, 24, 25, -1, -1, -1, -1, -1,   
				        -1, 26, 27, 28, 29, 30, 31, 32,   
				        33, 34, 35, 36, 37, 38, 39, 40,   
				        41, 42, 43, 44, 45, 46, 47, 48,   
				        49, 50, 51, -1, -1, -1, -1, -1];   
		        public static function encode(data:ByteArray):String {   
			            var out:Array = [];   
			            var i:int = 0;   
			            var j:int = 0;   
			            var r:int = data.length % 3;   
			            var len:int = data.length - r;   
			            var c:int;   
			            while (i < len) {   
				                c = data[i++] << 16 | data[i++] << 8 | data[i++];   
				                out[j++] = encodeChars[c >> 18] + encodeChars[c >> 12 & 0x3f] + encodeChars[c >> 6 & 0x3f] + encodeChars[c & 0x3f];   
			            }   
			            if (r == 1) {   
				                c = data[i++];   
				                out[j++] = encodeChars[c >> 2] + encodeChars[(c & 0x03) << 4] + "==";   
			            }   
			            else if (r == 2) {   
				                c = data[i++] << 8 | data[i++];   
				                out[j++] = encodeChars[c >> 10] + encodeChars[c >> 4 & 0x3f] + encodeChars[(c & 0x0f) << 2] + "=";   
			            }   
			            return out.join('');   
		        }   
		        public static function decode(str:String):ByteArray {   
			            var c1:int;   
			            var c2:int;   
			            var c3:int;   
			            var c4:int;   
			            var i:int;   
			            var len:int;   
			            var out:ByteArray;   
			            len = str.length;   
			            i = 0;   
			            out = new ByteArray();   
			            while (i < len) {   
				                // c1   
				                do {   
					                    c1 = decodeChars[str.charCodeAt(i++) & 0xff];   
				                } while (i < len && c1 == -1);   
				                if (c1 == -1) {   
					                    break;   
				                }   
				                // c2       
				                do {   
					                    c2 = decodeChars[str.charCodeAt(i++) & 0xff];   
				                } while (i < len && c2 == -1);   
				                if (c2 == -1) {   
					                    break;   
				                }   
				                out.writeByte((c1 << 2) | ((c2 & 0x30) >> 4));   
				                // c3   
				                do {   
					                    c3 = str.charCodeAt(i++) & 0xff;   
					                    if (c3 == 61) {   
						                        return out;   
					                    }   
					                    c3 = decodeChars[c3];   
				                } while (i < len && c3 == -1);   
				                if (c3 == -1) {   
					                    break;   
				                }   
				                out.writeByte(((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2));   
				                // c4   
				                do {   
					                    c4 = str.charCodeAt(i++) & 0xff;   
					                    if (c4 == 61) {   
						                        return out;   
					                    }   
					                    c4 = decodeChars[c4];   
				                } while (i < len && c4 == -1);   
				                if (c4 == -1) {   
					                    break;   
				                }   
				                out.writeByte(((c3 & 0x03) << 6) | c4);   
			            }   
			            return out;   
		        }   
	    }   
}